If considering wood you could get unfinished wood installed. Companies such as Wood Floor Accessories are a great supplier. Having it finished on site means a finish can be picked that works for your home. Each home has variables such as pets, different traffic and the owners desire to maintain the flooring or aversion to maintenance. Having wood finished on site has advantages. You can pick the highest quality product that works for your budget. The range of finishes available is quite wide. A professional company will try to understand your home and recommend the appropriate finish. They will also understand how easily the finish was can be renovated in the future. Amtico is an extremely robust product but being plastic, is just plastic flooring. It has its place, as does wood. In areas that have plenty of light surfaces, scratches show very easily on Amtico, Karndean etc. The manufacturers push a polishing maintenance product on consumers. However, this needs to be stripped and reapplied on a regular basis.

oh old post to practice, the obvious choice is first floor extention but this only if the ground foundation on the back supports for this floor. Its mirroring the outer wall of the ground floor so enough area, there also alternative option of cantilever steel beams or concrete floor slab for first floor side extention though maybe need additional permit . Bedroom 3 will slightly Bigger than original, Plan A Plan B - Very Narrow Hallway Plan C - With Cantilever

I'd also be inclined to swap them as Jonathan suggested. Check fire regulations, as perhaps you do need to rotate the stairs to allow an open kitchen. (I'm in the Netherlands so can't advise on these.)

I hope I am assuming correctly from the window placement that this house is detached? Maybe its a bit simplistic but swapping the kitchen with the reception room and extending into the left corner would give you a floorplan closer to what you had. You could also open up the wall between the dining room and the current reception room which would give you a decent sized kitchen diner. It would be good to see a floorplan of upstairs too. There is no question that there is less floorspace than where you were before. You will probably need a downstairs WC too maybe the current utility room?